One vertex per element, one color per generator, with an edge from x to x·s.
(2,5)(6,8)(9,10,15,17)(11,16,20,14)(12,18,21,24)(13,19,22,23)(25,26)(27,33)(28,32)(29,37)(30,31)(34,38)(35,39)(36,40)(3,7)(6,8)(9,11)(10,16)(12,13)(14,17)(15,20)(18,19)(21,22)(23,24)(26,31)(32,33)(34,37)(39,40) involution — undirected(1,2)(3,6)(4,5)(7,8)(10,17)(11,20)(13,22)(18,24)(25,27,30,28)(26,32,31,33)(29,35,38,36)(34,39,37,40)(9,12)(10,18)(11,13)(14,23)(15,21)(16,19)(17,24)(20,22)(25,28,30,27)(26,33,31,32)(29,35,38,36)(34,39,37,40)(1,3)(2,6)(4,7)(5,8)(9,13)(10,19)(11,21)(12,20)(14,18)(15,22)(16,24)(17,23)(25,26)(27,33)(28,32)(29,34)(30,31)(35,40)(36,39)(37,38) involution — undirected(1,2)(3,6)(4,5)(7,8)(9,14)(10,20)(11,17)(12,19)(13,18)(15,16)(21,23)(22,24)(25,29,30,38)(26,34,31,37)(27,35,28,36)(32,39,33,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.